Evaporator, manufacturing method of the same, header for evaporator and refrigeration system

ABSTRACT

The evaporator includes the upper side and lower header members  10  and  50  disposed at the upper and lower end of the core  1.  One end of each tube  6  constituting the upstream-side tube group P 1  is connected to the inlet-side tank  11,  while the other end to the lower header member  50.  One end of each tube  7  constituting the downstream-side tube group P 2  is connected to the outlet-side tank  12,  while the other end to the lower header member  50.  The refrigerant flowed into the inlet-side tank  11  is introduced into the outlet-side tank  12  by passing through the upstream-side tube group P 1 , the lower header member  50  and the downstream-side tube group P 2 , so that the refrigerant evaporates by exchanging heat with ambient air A. Accordingly, it improves the heat exchange performance and decreases the thickness.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims the benefit of priorityfrom U.S. Ser. No. 10/480,259, filed Dec. 18, 2003, which is a nationalstage of PCT/JP02/06046, filed Jun. 17, 2002, which is based upon U.S.Ser. No. 60/303,145, filed on Jul. 6, 2001, and further is based uponand claims the benefit of priority to Japanese Patent Application No.2001-183062, filed on Jun. 18, 2001, the entire contents of each ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to, for example, an evaporator for carair-conditioners or room air-conditioners, a manufacturing methodthereof, a header member for an evaporator and a refrigeration system.

BACKGROUND ART

A refrigeration system for car air-conditioners has a refrigerationcycle. In this cycle, a gaseous refrigerant of high temperature and highpressure sent out of a compressor is condensed by a condenser and thenmade into mist-like refrigerant including a gaseous phase and a liquidphase by decompressing means such as an expansion valve. Then,. themist-like refrigerant evaporates while passing through an evaporator.Thereafter, the evaporated refrigerant returns to the compressor.

As a conventional evaporator used in the aforementioned refrigerationsystem, a laminated type evaporator is mainly used. The laminated typeevaporator includes a plurality of tubular elements laminated inlaminating direction and fins each interposed between the adjacenttubular elements, wherein each tubular element is formed by coupling apair of plate-shaped formed plates in a face-to-face manner.

This kind of laminated type evaporator is large in cooling capacity andis low in air-side pressure loss, and therefore has excellentcharacteristics. In recent years, in view of an odor problem of aninside of a car or the like, an odor removal filter is sometimesinstalled in front of the evaporator. In this case, in order to securethe mounting space for such a filter, the evaporator tends to berequired to reduce the thickness.

In meeting such a demand of reducing the thickness of the aforementionedlaminated type evaporator, the following drawbacks have became clear.

First, since each tubular element having heat exchanging passages isformed by coupling a pair of plate-shaped formed plates formed bydrawing processing using a press in a face-to-face manner, the portionswhere the pair of formed plates directly contact, i.e., the portionsother than the heat exchanging passages, likely increase. Consequently,the cross-sectional area of the refrigerant passages decrease, which maycause high refrigerant side pressure drop and deteriorate theperformance. As this countermeasure, it is considered to increase theheight of the refrigerant passage by increasing the drawing amount ofthe formed plate to thereby enlarge the cross-sectional area of thepassage. However, according this proposal, the tubular element becomesthick, and therefore the air-side passage between the adjacent tubularelements becomes smaller, resulting in a reduced size of the findisposed in the air-side passage. Consequently, there is a possibilitythat the air-side pressure drop increases and that the heat transferringarea of the fin decreases, which in turn causes a deterioration of theperformance.

Second, in the aforementioned laminated type evaporator, the fin doesnot comes into contact with a portion where the pair of formed platesdirectly contact each other, and therefore surface efficiencydeteriorates. Accordingly, the more the thickness of the tubular elementbecomes, the more the rate of non-contact portion of the fin increases.This may cause a deterioration of the cooling performance.

Third, in the aforementioned laminated type evaporator, since the tankportion and the tube portion (heat exchanging medium passage portion)are integrally formed in the plate-shaped formed plate, the tank portionwhere higher pressure resistance is required is also formed by a drawingprocessing. Accordingly, the thickness of the tank portion tends tobecome thinner than that of the tube portion (heat exchange mediumpassage portion). Accordingly, It is necessary to design the wallthickness on the basis of the tank portion. As a result, even if thetube portion has enough pressure resistance, it is impossible to furtherreduce the wall thickness, which may not meet the demand of reducingweight.

As will be apparent from the above, in a laminated type evaporator, itis difficult to further reduce the thickness while achieving sufficientperformance.

The present invention was made in view of the aforementionedcircumstances, it is an object of the present invention to provide anevaporator capable of reducing the weight and the size while maintainingsufficient heat exchanging performance, the manufacturing method of theevaporator, a header member for the evaporator and a refrigerationsystem.

Another objects of the present invention will be apparent from thefollowing explanation.

DISCLOSURE OF INVENTION

According to the first aspect of the present invention, an evaporatorcomprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube groups including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-side tank disposed along one end side of the upstream-side heatexchanging tube group;

an outlet-side tank disposed along one end side of the downstream-sideheat exchanging tube group; and

a refrigerant turning member disposed along the other end side of boththe heat exchanging tube groups,

wherein each one end of the heat exchanging tubes constituting theupstream-side heat exchanging tube group is connected to the inlet-sidetank, while the other end thereof is connected to the refrigerantturning member, and

wherein each one end of the heat exchanging tubes constituting thedownstreamn-side heat exchanging tube group is connected to theoutlet-side tank, while the other end thereof is connected to therefrigerant turning member,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the refrigerant turning member and the downstream-side heat exchangingtube group, while the refrigerant passing through both the heatexchanging tube groups evaporates by exchanging heat with ambient air.

In the evaporator of the present invention, since the refrigerantpassage is formed into a U-shape by the upstream-side anddownstream-side heat exchanging tube groups, the refrigerant pressuredrop can be decreased. Accordingly, the refrigerant passagecross-sectional area can be reduced, and the tube height of the heatexchanging tube can be lowered. Furthermore, since the tube height canbe lowered, the number of heat exchanging tubes can be increased withoutincreasing the core dimension, resulting in an enhanced refrigerantdispersibility.

In the present invention, it is preferable that the inlet-side tank isprovided with refrigerant distributing resistance means whichdistributes the refrigerant in a longitudinal direction of theinlet-side tank, or the outlet-side tank is provided withuneven-distribution-flow preventing resistance means which preventsuneven-distribution-flow of refrigerant.

In cases where these structures are adopted, the refrigerant passingthrough the heat exchanging tube groups is distributed equallythroughout the core, and therefore the heat exchange can be performedefficiently throughout the core.

In order to attain the aforementioned object, according to the secondaspect of the present invention, an evaporator comprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube groups including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-and-outlet-side header member disposed along one end side ofboth the heat exchanging tube groups; and

a refrigerant-turn-side header member disposed along the other end sideof both the heat exchanging tube groups,

wherein an inside of the inlet-and-outlet-side header member is dividedfront and rear by a partition into a front-side portion and a rear-sideportion, wherein the front-side portion constitutes an inlet-side tankand the rear-side portion constitutes an outlet-side tank,

wherein one end of each of the heat exchanging tubes constituting theupstream-side heat exchanging tube group is connected to the inlet-sidetank of the inlet-and-outlet-side header member, while the other endthereof is connected to the refrigerant-turn-side header member, and

wherein one end of each of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is connected to theoutlet-side tank of the inlet-and-outlet-side header member, while theother end thereof is connected to the refrigerant-turn-side headermember,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the refrigerant-turn-side member and the downstream-side heat exchangingtube group, while the refrigerant passing through both the heatexchanging tube groups evaporates by exchanging heat with ambient air.

In the evaporator of this invention, since the refrigerant passage isformed into a simple U-shape like in the aforementioned evaporator, therefrigerant flow resistance can be decreased, resulting in enhancedrefrigerant dispersibility.

In the evaporator according to the present invention, it is preferablethat the inlet-and-outlet-side header member includes aninlet-and-outlet-side header plate to which one end of each of the heatexchanging tubes is fixed in a penetrated manner and aninlet-and-outlet-side header cover attached to the header plate so as tocover one surface side of the header plate.

Furthermore, in the present invention, it is preferable that therefrigerant-turn-side header member includes a refrigerant-turn-sideheader plate to which the other end of each of the heat exchanging tubesis fixed in a penetrated manner and a refrigerant-turn-side header coverattached to the header plate so as to cover the other surface of theheader plate.

In the present invention, it is preferable to employ-the followingstructures in order to enhance the refrigerant dispersibility.

That is, in the present invention, it is preferable that refrigerantdistributing resistance means which distributes the refrigerant in alongitudinal direction of the inlet-side tank is provided in an insideof the inlet-side tank.

As the aforementioned refrigerant distributing resistance means, it ispossible to employ a refrigerant distributing resistance plate whichdivides the inlet-side tank into an upper space and a lower space andhas a plurality of refrigerant passage apertures formed at intervalsalong the longitudinal direction of the inlet-side tank.

Furthermore, it is preferable that the plurality of refrigerant passageapertures of the refrigerant distributing resistance plate includeapertures different in size.

Furthermore, it is preferable that the inlet-and-outlet-side headermember has a refrigerant inlet for introducing refrigerant into theinlet-side tank, and wherein the plurality of refrigerant passageapertures of the refrigerant distributing resistance plate are formed sothat the refrigerant passage aperture increases in size as it goes awayfrom the refrigerant inlet, or that the refrigerant inlet is formed at alongitudinal middle position of the inlet-side tank, and wherein therefrigerant passage apertures formed in the refrigerant distributingresistance plate and located apart from the refrigerant inlet is formedto have a size larger than a size of the refrigerant passage aperturelocated near the refrigerant inlet.

In the present invention, it is also possible to employ the structurethat the refrigerant inlet is provided at a longitudinal end portion ofthe inlet-side tank.

In the present invention, it is preferable to employ the followingstructures in order to further enhance the refrigerant dispersibility.

That is, in the present invention, it is preferable thatuneven-distribution-flow preventing resistance means for preventinguneven-refrigerant-flow is provided within the outlet-side tank of theinlet-and-outlet-side header member.

As this uneven-distribution-flow preventing resistance means, it ispreferable to employ an uneven-distribution-flow preventing resistanceplate which divides the outlet-side tank into an upper space and a lowerspace and has a plurality of refrigerant passage apertures formed atintervals along a longitudinal direction of the outlet-side tank.

Furthermore, in the present invention, it is preferable that a distancebetween adjacent refrigerant passage apertures formed in theuneven-distribution-flow preventing resistance plate falls within therange of 1 to 4 times as long as a distance between adjacent heatexchanging tubes.

In cases where this structure is employed, the refrigerant can be flowedevenly thorough the entire core, resulting in enhanced refrigerationperformance.

Furthermore, in the present invention, it is preferable that therefrigerant passage apertures formed in the uneven-distribution-flowpreventing resistance plate are offset from a widthwise central portionof the heat exchanging tube toward a windward side relative to an airintroducing direction.

In cases where this structure is employed, it is possible to prevent theliquefied refrigerant flow from the inlet-and-outlet-side header member,resulting in a stable expansion valve control.

In the present invention, it is more preferable that theinlet-and-outlet-side header member has a refrigerant outlet throughwhich refrigerant flows out of the outlet-side tank, and wherein across-sectional area of a refrigerant passage aperture located in themost distant position from the refrigerant outlet among the refrigerantpassage apertures formed in the uneven-distribution-flow preventingresistance plate is set to 7 mm.sup.2 or less.

In cases where this structure is employed, the dispersibility of therefrigerant can be further enhanced.

Furthermore, in the present invention, it is possible to employ thestructure that the refrigerant outlet is provided at a longitudinalmiddle portion of the outlet-side tank, or that the refrigerant outletis provided at a longitudinal end portion of the outlet-side tank.

Furthermore, in the present invention, it is preferable that across-sectional area between the uneven-distribution-flow preventingresistance plate and an end portion of the heat exchanging tube in theoutlet-side tank is 1 to 5 times as large as a passage cross-sectionalarea of the heat exchanging tube.

That is, by employing this structure, it is possible to prevent anincrease of flow resistance between the uneven-distribution-flowpreventing resistance plate and an end portion of the heat exchangingtube and secure an appropriate space in the header member.

In the present invention, it is preferable that a total cross-sectionalarea of the refrigerant passage apertures formed in theuneven-distribution-flow preventing resistance plate is larger than atotal passage cross-sectional area of the heat exchanging tubes at thedownstream-side heat exchanging tube group.

In cases where this structure is employed, it is possible to prevent anincrease of flow resistance and further enhance the dispersibility ofthe refrigerant.

Furthermore, in the present invention, in order to prevent an increaseof flow resistance and further enhance the dispersibility of therefrigerant, it is preferable that each of the refrigerant passageaperture formed in the uneven-distribution-flow preventing resistanceplate is formed into a round shape, or that the refrigerant passageaperture formed in the uneven-distribution-flow preventing resistanceplate is formed into an ellipse shape or a rectangular shape having amajor axis along a width direction of the heat exchanging tube.

In the present invention, it is preferable that corresponding heatexchanging tubes of both the heat exchanging tube groups are integrallyconnected, or that the heat exchanging tube is an extruded tube obtainedby extrusion molding.

In the present invention, it is possible to employ the structure that atube height of the heat exchanging tube falls within the range of from0.75 to 1.5 mm.

According to the third aspect of the present invention, an evaporatorcomprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube group including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-and-outlet-side header member disposed along one end side ofboth the heat exchanging tube groups; and

a refrigerant-turn-side header member disposed along the other end sideof both the heat exchanging tube groups,

wherein an inside of the inlet-and-outlet-side header member is dividedinto an inlet-side tank and an outlet-side tank,

wherein the refrigerant-turn-side header member includes at least twopress-formed metal plate members,

wherein an inside of the refrigerant-turn-side header member is dividedinto an inflow-side tank and an outflow-side tank by arefrigerant-turn-side partition, and both the tanks being communicatedby communication apertures provided in the partition,

wherein one end of each of the heat exchanging tubes constituting theupstreamn-side heat exchanging tube group is connected to the inlet-sidetank of the inlet-and-outlet-side header member, while theother-end-thereof is connected to the inflow-side tank of therefrigerant-turn-side header member, and

wherein one end of each of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is connected to theoutlet-side tank of the inlet-and-outlet-side header member, while theother end thereof is connected to the outflow-side tank of therefrigerant-turn-side header member,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the inflow-side tank, the apertures, the outflow-side tank and thedownstream-side heat exchanging tube group, while the refrigerantpassing through both the heat exchanging tube groups evaporates byexchanging heat with ambient air.

In the third aspect of the present invention, in the same way as in thefirst and second inventions, since the refrigerant passage is formedinto a simple U-shape, the refrigerant pressure drop can be decreased,resulting in an enhanced refrigerant dispersibility. Furthermore, sincethe press-formed metal plate member is used as the inlet-and-outlet-sideheader member, the header material can be continuously manufactured froma coiled metal material, which can increase the productivity.

Furthermore, since the header material is constituted by a plate member,as this header material, it is possible to use a brazing sheet in whichclad materials such as brazing materials or sacrificial materialslaminated on at least one surface thereof Thus, the brazability andcorrosion resistance can be improved.

Furthermore, in the present invention, it is preferable that therefrigerant-turn-side header member includes a header plate to which oneend of each of the heat exchanging tubes is fixed in a penetrated mannerand a header cover attached to the header plate so as to cover onesurface side of the header plate, and wherein the refrigerant-turn-sidepartition is formed by folding a widthwise middle portion of a metalplate member constituting the header cover along a longitudinaldirection thereof.

That is, in cases where this structure is employed, since the partitioncan be integrally formed by press forming processing, the productivitycan be further improved. Furthermore, since the partition isconstituted-by folded plate portions, enough strength can be achieved bythe partition, resulting in further enhancing pressure resistance of theheader member.

Furthermore, in the present invention, it is preferable that therefrigerant-turn-side partition has at a tip portion thereof engagingprotrusions at certain intervals along a longitudinal direction thereof,wherein the header plate has at a widthwise middle portion thereofengaging apertures corresponding to the engaging protrusions at certainintervals along a longitudinal direction thereof, and wherein theengaging protrusions are inserted and fixed in the engaging apertures bycaulking processing.

In cases where this structure is employed, the positioning of the headercover relative to the header plate can be performed more assuredly.

Furthermore, in the present invention, it is more preferable that themetal plate member constituting the refrigerant-turn-side header memberis formed by an aluminum brazing sheet having an aluminum core and abrazing layer laminated on at least one side of the core.

That is, in cases where this structure is employed, the brazability ofthe entire evaporator can be further enhanced.

Furthermore, in the present invention, it is preferable that the brazingsheet has the brazing layer laminated at an external surface sidethereof, and wherein the brazing layer contains zinc.

That is, in cases where this structure is employed, asacrificial-corrosion layer can be formed on the external surface of therefrigerant-turn-side header member, resulting in an enhanced corrosionresistance.

Furthermore, in the present invention, it is preferable that a thicknessof the header cover is thinner than that of the header plate.

That is, in cases where this structure is employed, the size and weightof the header member, or the entire evaporator, can be reduced whilekeeping enough pressure strength.

In the third aspect of the present invention, it is preferable that theinlet-and-outlet-side header member includes at least two press-formedmetal plate members.

That is, in cases where this structure is employed, the productivity andbrazability of the inlet-and-outlet-side header member can be furtherimproved.

In the third aspect of the present invention, it is preferable toconstitute the inlet-and-outlet-side header member as follows in thesame way as in the refrigerant-turn-side header member.

That is, in the third aspect of the present invention, it is preferablethat the inlet-and-outlet-side header member has a header plate to whichan end portion of each of the exchanging tubes is fixed in a penetratedmanner and a header cover attached to the header plate so as to coverone surface side thereof, and wherein the inlet-and-outlet-sidepartition is formed by folding a widthwise middle portion of a metalplate member constituting the header cover along a longitudinaldirection thereof.

That is, in the third aspect of the present invention, it is preferablethat the inlet-and-outlet-side partition has at a tip portion thereofengaging protrusions at certain intervals along a longitudinal directionthereof, wherein the header plate has at a widthwise middle portionthereof engaging apertures corresponding to the engaging protrusions atcertain intervals along a longitudinal direction thereof, and whereinthe engaging protrusions are inserted in and fixed to the engagingapertures by caulking processing.

Further, in the third aspect of the present invention, it is preferablethat the metal plate member constituting the inlet-and-outlet-sideheader member is formed by an aluminum brazing sheet having a brazinglayer laminated on at least one side thereof.

Further, in the third aspect of the present invention, it is preferablethat the brazing sheet has the brazing layer laminated at an externalsurface side thereof, and wherein the brazing layer contains zinc.

Further, in the third aspect of the present invention, it is preferablethat a thickness of the header cover is thinner than that of the headerplate.

According to the fourth aspect of the present invention, an evaporatorcomprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube groups including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-and-outlet-side header member disposed along one end side ofboth the heat exchanging tube groups; and

a refrigerant-turn-side header member disposed along the other end sideof both the heat exchanging tube groups,

wherein the inlet-and-outlet-side header member includes aninlet-and-outlet-side header plate, an inlet-and-outlet-side headercover attached to the header plate so as to cover one surface side ofthe header plate and a partition for dividing an inside of theinlet-and-outlet-side header member into an inlet-side tank and anoutlet-side tank,

wherein the refrigerant-turn-side header member includes arefrigerant-turn-side header plate and a refrigerant-turn-side headercover attached to the header plate so as to cover one surface side ofthe header plate, one of the refrigerant-turn-side header plate and therefrigerant-turn-side header cover being formed by a press-formed metalplate member, and the other thereof being formed by an extruded moldedarticle,

wherein one end of each of the heat exchanging tubes constituting theupstream-side heat exchanging tube group is fixed to theinlet-and-outlet-side header plate in a penetrated manner to thereby beconnected to the inlet-side tank, while the other end thereof isconnected to the refrigerant-turn-side header plate in a penetratedmanner,

wherein one end of each of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is fixed to theinlet-and-outlet-side header member to thereby be connected to theoutlet-side tank, while the other end thereof is connected to therefrigerant-turn-side header member in a predetermined manner,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the refrigerant-turn-side header member and the downstream-side heatexchanging tube group, while the refrigerant passing through both theheat exchanging tube groups evaporates by exchanging heat with ambientair.

In the fourth aspect of the present invention, in the same way as in thethird aspect of the present invention, since the refrigerant passage isformed into a simple U-shape, the refrigerant pressure drop can bereduced and the dispersibility of the refrigerant can be increased.Furthermore, in the refrigerant-turn-side header member, theproductivity, brazability and corrosion resistance can be improved.

In the fourth aspect of the present invention, it is preferable that oneof the inlet-and-outlet-side header plate and the inlet-and-outlet-sideheader cover is formed by a press-formed metal plate member and theother thereof is formed by an extruded molded article.

In cases where this structure is employed, in the inlet-and-outlet-sideheader cover, the productivity and brazability can also be improved.

According to the fifth aspect of the present invention, a method ofmanufacturing an evaporator comprises the steps of:

a step of preparing a plurality of heat exchanging tubes constituting anupstream-side heat exchanging tube group and a downstream-side heatexchanging tube group to be disposed front and rear;

a step of preparing an inlet-side tank to be disposed along one end sideof the upstream-side heat exchanging tube group;

a step of preparing an outlet-side tank to be disposed along one endside of the downstream-side heat exchanging tube group;

a step of preparing a refrigerant turning member to be disposed alongthe other end side of both the heat exchanging tubes groups;

a step of brazing one end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to theinlet-side tank;

a step of brazing the other end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to therefrigerant turning member;

a step of brazing one end of each of the heat exchanging tubesconstituting the downstream-side heat exchanging tube group; and

a step of brazing the other end of each of the heat exchanging tubesconstituting the downstream-side heat exchanging tube group to therefrigerant turning member;

wherein refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank by passing through the upstream-side heatexchanging tube group, the refrigerant turning member and thedownstream-side heat exchanging tube group, and

wherein the refrigerant passing through both the-heat exchanging tubegroups constitutes a refrigerant circuit in which the refrigerantevaporates by exchanging heat with ambient air.

In the fifth aspect of the present invention, the evaporator accordingto the first aspect of the present invention can be manufacturedassuredly.

In the fifth aspect of the present invention, it is preferable that thebrazing steps are collectively performed by furnace brazing processing.

The sixth aspect of the present invention specifies one embodiment ofthe manufacturing process of the evaporator according to the secondaspect of the present invention.

That is, according to the sixth aspect of the present invention, amethod of manufacturing an evaporator comprises the steps of:

a step of preparing heat exchanging tubes constituting an upstream-sideheat exchanging tube group and a downstream-side heat exchanging tubegroup to be disposed front and rear;

a step of preparing an inlet-and-outlet-side header member to bedisposed along one end side of both the heat exchanging tube groups,wherein an inside of the header member is divided by a partition frontand rear into one side space constituting an inlet-side tank and theother side space constituting an outlet-side tank;

a step of preparing a refrigerant-turn-side header member to be disposedalong the other end side of both the heat exchanging tube groups;

a step of brazing one end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to aninlet-side tank of the inlet-and-outlet-side header;

a step of brazing the other end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to therefrigerant-turn-side header member;

a step of brazing one end of each of the heat exchanging tubesconstituting the downstream-side heat exchanging tube group to theoutlet-side tank of the inlet-and-outlet-side header; and

a step of brazing the other end of each of the heat exchanging tubes ofthe downstream-side heat exchanging tube group to therefrigerant-turn-side header member;

wherein refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank by passing through the upstream-side heatexchanging tube group, the refrigerant-turn-side header member and thedownstream-side heat exchanging tube group, and

wherein the refrigerant passing through both the heat exchanging tubegroups constitutes a refrigerant circuit in which the refrigerantevaporates by exchanging heat with ambient air.

According to the sixth aspect of the present invention, the evaporatoraccording to the second aspect of the present invention can bemanufactured assuredly.

In the sixth aspect of the present invention, it is preferable that thebrazing steps are collectively performed by furnace brazing processing.

The seventh aspect of the present invention specifies an embodiment ofthe manufacturing process of the evaporator according to the thirdaspect of the present invention.

That is, according to the seventh aspect of the present invention, themethod comprises the steps of:

a step of preparing heat exchanging tubes constituting an upstream-sideheat exchanging tube group and a downstream-side heat exchanging tubegroup to be disposed front and rear;

a step of preparing an inlet-and-outlet-side header member to bedisposed along one end of both the heat exchanging tube groups, aninside of the header member being divided into an inlet-side tank and anoutlet-side tank;

a step of preparing a refrigerant-turn-side header member to be disposedalong the other end side of both the heat exchanging tube groups, therefrigerant-turn-side header member including at least two press-formedmetal plate members, and an inside of the header member being divided bya refrigerant-turn-side partition into an inflow-side tank and anoutflow-side tank, and the both tanks being communicated each other viacommunication apertures formed in the partition;

a step of brazing one end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to aninlet-side tank of the inlet-and-outlet-side header;

a step of brazing the other end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to aninflow-side tank of the refrigerant-turn-side header member;

a step of brazing one end of each of the heat exchanging tubesconstituting the downstream-side heat exchanging tube group to theoutlet-side tank of the inlet-and-outlet-side header; and

a step of brazing the other end of each of the heat exchanging tubes ofthe downstream-side heat exchanging tube group to an outflow-side tankof the refrigerant-turn-side header member;

wherein refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank by passing through the upstream-side heatexchanging tube group, the inflow-side tank, the communicationapertures, the outflow-side tank and the downstream-side heat exchangingtube group, and

wherein the refrigerant passing through both the heat exchanging tubegroups constitutes a refrigerant circuit in which the refrigerantevaporates by exchanging heat with ambient air.

According to the seventh aspect of the present invention, the evaporatoraccording to the third aspect of the present invention can bemanufactured assuredly.

In the seventh aspect of the present invention, it is preferable thatthe brazing steps are collectively performed by furnace brazingprocessing.

The eighth aspect of the present invention specifies an embodiment ofthe manufacturing process of the evaporator according to the fourthaspect of the present invention.

According to the eighth aspect of the present invention, a method ofmanufacturing an evaporator comprises the steps of:

a step of preparing heat exchanging tubes constituting an upstreamn-sideheat exchanging tube group and a downstream-side heat exchanging tubegroup to be disposed front and rear;

a step of preparing an inlet-and-outlet-side header member to bedisposed along one end of both the heat exchanging tube groups, whereinthe header member includes an inlet-and-outlet-side header plate, aninlet-and-outlet-side header cover attached to the header plate so as tocover one surface side thereof and a partition for dividing an inside ofthe inlet-and-outlet-side header member into an inlet-side tank and anoutlet-side tank;

a step of preparing a refrigerant-turn-side header member to be disposedalong the other end side of both the heat exchanging tube groups,wherein the refrigerant-turn-side header member includes arefrigerant-turn-side header plate and a refrigerant-turn-side headercover attached to the header plate so as to cover one side surfacethereof, one of the refrigerant-turn-side header plate and therefrigerant-turn-side header cover being made of a press-formed metalplate, and the other thereof being made of an extruded molded article;

a step of brazing one end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to the headerplate of the inlet-and-outlet-side header to thereby be connected to theinlet-side tank;

a step of brazing the other end of each of the heat exchanging tubesconstituting the upstream-side heat exchanging tube group to the headerplate of the refrigerant-turn-side header member;

a step of brazing one end of each of the heat exchanging tubesconstituting the downstream-side heat exchanging tube group to theheader plate of the inlet-and-outlet-side header to thereby be connectedto the outlet-side tank; and

a step of brazing the other end of each of the heat exchanging-tubesconstituting the downstream-side heat exchanging tube group to theheader plate of the refrigerant-turn-side header member;

wherein refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank by passing through the upstream-side heatexchanging tube group, the refrigerant-turn-side header member and thedownstream-side heat exchanging tube group, and

wherein the refrigerant passing through both the heat exchanging tubegroups constitutes a refrigerant circuit in which the refrigerantevaporates by exchanging heat with ambient air.

According to the eight aspect of the present invention, the evaporatoraccording to the fourth aspect of the present invention can bemanufactured assuredly.

In the eighth aspect of the present invention, in order to improve theproductivity, it is preferable that the brazing steps are collectivelyperformed by furnace brazing processing.

Furthermore, in the eighth aspect of the present invention, it ispreferable that a step of forming a zinc diffusion layer on a surface ofeach-of the header members is performed by applying a flux containingzinc on the surface before performing the furnace brazing processing.

In this case, a sacrifice layer can be assuredly formed on the externalsurface of the header member, which can improve the corrosionresistance.

The ninth aspect of the present invention specifies aninlet-and-outlet-side header member applicable to the aforementionedthird or fourth aspect of the present invention.

That is, according to the ninth aspect of the present invention, aninlet-and-outlet-side header member for an evaporator with a coreincluding an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group disposed front and rear, eachof heat exchanging tube group including a plurality of heat exchangingtubes arranged in parallel with each other at certain intervals,comprises:

a header plate for fixing an end portion of each of the heat exchangingtubes in a penetrated manner;

a header cover attached to the header plate so as to cover one surfaceside thereof; and

a partition for forming an inlet-side tank and an outlet-side tank bydividing a hollow portion surrounded by the header plate and the headercover front and rear;

wherein at least one of the header plate and the header cover is apress-formed metal plate, and

wherein refrigerant flowed into the inlet-side tank is introduced intothe upstream-side heat exchanging tube group, while refrigerant passingthrough the downstream-side heat exchanging tube group is introducedinto the outlet-side tank.

In the ninth aspect of the present invention, it is possible to employthe structure that the header plate and the header cover are formed by apress-formed metal plate member, and wherein the partition is integrallyformed with the header cover by folding a widthwise middle portion ofthe metal plate constituting the header cover along a longitudinaldirection thereof, or that one of the header plate and the header coveris a press-formed metal plate, and the other thereof is an extrudedmolded article.

The tenth aspect of the present invention specifies arefrigerant-turn-side header member applicable to the aforementionedthird or fourth aspect of the present invention.

That is, according to the tenth aspect of the present invention, arefrigerant-turn-side header member for an evaporator with a coreincluding an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group disposed front and rear, eachof heat exchanging tube group including a plurality of heat exchangingtubes arranged in parallel with each other at certain intervals,comprises:

a header plate for fixing an end portion of each of the heat exchangingtubes in a penetrated manner;

a header cover attached to the header plate so as to cover one surfaceside thereof; and

a partition for forming an inflow-side tank and an outflow-side tank bydividing a hollow portion surrounded by the header plate and the headercover front and rear, the partition having communication apertures forcommunicating with the tanks;

wherein at least one of the header plate and the header cover is apress-formed metal plate, and

wherein refrigerant passing through the upstream-side heat exchangingtube group is introduced into the inflow-side tank and then introducedinto the outflow-side tank via the communication apertures, while therefrigerant in the outflow-side tank is introduced into thedownstream-side heat exchanging tube group.

In the tenth aspect of the present invention, it is possible to employthe structure that both of the header plate and the header cover areformed by a press-formed metal plate member respectively, and whereinthe partition is integrally formed with the header cover by folding awidthwise middle portion of the metal plate constituting the headercover along a longitudinal direction thereof, or that one of the headerplate and the header cover is a press-formed metal plate, and the otherthereof is an extruded molded article.

The eleventh aspect of the present invention specifies a refrigerationsystem utilizing the evaporator according to the first aspect of thepresent invention.

According to the eleventh aspect of the present invention, arefrigeration system in which refrigerant compressed by a compressor iscondensed by a condenser into a condensed refrigerant, then thecondensed refrigerant is passed through a decompressing device into adecompressed refrigerant, and thereafter the decompressed refrigerant isevaporated by an evaporator and then returns to the compressor, theevaporator comprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube groups including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-side tank disposed along one end side of the upstream-side heatexchanging tube group;

an outlet-side tank disposed along one end side of the downstream-sideheat exchanging tube group; and

a refrigerant turning member disposed along the other end side of boththe heat exchanging tube groups,

wherein each one end of the heat exchanging tubes constituting theupstream-side heat exchanging tube group is connected to the inlet-sidetank, while the other end thereof is connected to the refrigerantturning member, and

wherein each one end of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is connected to theoutlet-side tank, while the other end thereof is connected to therefrigerant turning member, whereby refrigerant flowed into theinlet-side tank is introduced into the outlet-side tank via theupstream-side heat exchanging tube group, the refrigerant turning memberand the downstream-side heat exchanging tube group, while therefrigerant passing through both the heat exchanging tube groupsevaporates by exchanging heat with ambient air.

The twelfth aspect of the present invention specifies a refrigerationsystem utilizing the evaporator according to the second aspect of thepresent invention.

According to the twelfth aspect of the present invention, arefrigeration system in which refrigerant compressed by a compressor iscondensed by a condenser into a condensed refrigerant, then thecondensed refrigerant is passed through a decompressing device into adecompressed refrigerant, and thereafter the decompressed refrigerant isevaporated by an evaporator and then returns to the compressor, anevaporator, comprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube groups including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-and-outlet-side header member disposed along one end side ofboth the heat exchanging tube groups; and

a refrigerant-turn-side header member disposed along the other end sideof both the heat exchanging tube groups,

wherein an inside of the inlet-and-outlet-side header member is dividedfront and rear by a partition into a front-side portion and a rear-sideportion, wherein the front-side portion constitutes an inlet-side tankand the rear-side portion constitutes an outlet-side tank,

wherein one end of each of the heat exchanging tubes constituting theupstreamn-side heat exchanging tube group is connected to the inlet-sidetank of the inlet-and-outlet-side header member, while the other endthereof is connected to the refrigerant-turn-side header member, and

wherein one end of each of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is connected to theoutlet-side tank of the inlet-and-outlet-side header member, while theother end thereof is connected to the refrigerant-turn-side headermember,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the refrigerant-turn-side member and the downstream-side heat exchangingtube group, while the refrigerant passing through both the heatexchanging tube groups evaporates by exchanging heat with ambient air.

The thirteenth aspect of the present invention specifies a refrigerationsystem utilizing the evaporator according to the third aspect of thepresent invention.

According to the thirteenth aspect of the present invention, arefrigeration system in which refrigerant compressed by a compressor iscondensed by a condenser into a condensed refrigerant, then thecondensed refrigerant is passed through a decompressing device into adecompressed refrigerant, and thereafter the decompressed refrigerant isevaporated by an evaporator and then returns to the compressor, anevaporator, comprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube group including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-and-outlet-side header member disposed along one end side ofboth the heat exchanging tube groups; and

a refrigerant-turn-side header member disposed along the other end sideof both the heat exchanging tube groups,

wherein an inside of the inlet-and-outlet-side header member is dividedinto an inlet-side tank and an outlet-side tank,

wherein the refrigerant-turn-side header member includes at least twopress-formed metal plate members,

wherein an inside of the refrigerant-turn-side header member is dividedinto an inflow-side tank and an outflow-side tank by arefrigerant-turn-side partition, and both the tanks being communicatedby communication apertures provided in the partition,

wherein one end of each of the heat exchanging tubes constituting theupstream-side heat exchanging tube group is connected to the inlet-sidetank of the inlet-and-outlet-side header member, while the other endthereof is connected to the inflow-side tank of therefrigerant-turn-side header member, and

wherein one end of each of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is connected to theoutlet-side tank of the inlet-and-outlet-side header member, while theother end thereof is connected to the outflow-side tank of therefrigerant-turn-side header member,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the inflow-side tank, the apertures, the outflow-side tank and thedownstream-side heat exchanging tube group, while the refrigerantpassing through both the heat exchanging tube groups evaporates byexchanging heat with ambient air.

The fourteenth aspect of the present invention specifies a refrigerationsystem utilizing the evaporator according to the fourth aspect of thepresent invention.

According to the fourteenth aspect of the present invention, arefrigeration system in which refrigerant compressed by a compressor iscondensed by a condenser into a condensed refrigerant, then thecondensed refrigerant is passed through a decompressing device into adecompressed refrigerant, and thereafter the decompressed refrigerant isevaporated by an evaporator and then returns to the compressor, anevaporator, comprises:

a core including an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group arranged front and rear, eachof the heat exchanging tube groups including a plurality of heatexchanging tubes disposed parallel with each other at certain intervals;

an inlet-and-outlet-side header member disposed along one end side ofboth- the heat exchanging tube groups; and

a refrigerant-turn-side header member disposed along the other end sideof both the heat exchanging tube groups,

wherein the inlet-and-outlet-side header member includes aninlet-and-outlet-side header plate, an inlet-and-outlet-side headercover attached to the header plate so as to cover one surface side ofthe header plate and a partition for dividing an inside of theinlet-and-outlet-side header member into an inlet-side tank and anoutlet-side tank,

wherein the refrigerant-turn-side header member includes arefrigerant-turn-side header plate and a refrigerant-turn-side headercover attached to the header plate so as to cover one surface side ofthe header plate, one of the refrigerant-turn-side header plate and therefrigerant-turn-side header cover being formed by a press-formed metalplate member, and the other thereof being formed by an extruded moldedarticle,

wherein one end of each of the heat exchanging tubes constituting theupstream-side heat exchanging tube group is fixed to theinlet-and-outlet-side header plate in a penetrated manner to thereby beconnected to the inlet-side tank, while the other end thereof isconnected to the refrigerant-turn-side header plate in a penetratedmanner,

wherein one end of each of the heat exchanging tubes constituting thedownstream-side heat exchanging tube group is fixed to theinlet-and-outlet-side header member to thereby be connected to theoutlet-side tank, while the other end thereof is connected to therefrigerant-turn-side header member in a predetermined manner,

whereby refrigerant flowed into the inlet-side tank is introduced intothe outlet-side tank via the upstream-side heat exchanging tube group,the refrigerant-turn-side header member and the downstream-side heatexchanging tube group, while the refrigerant passing through both theheat exchanging tube groups evaporates by exchanging heat with ambientair.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A shows a front view showing a first embodiment according to thepresent invention.

FIG. 1B is a side view showing the evaporator of the first embodiment.

FIG. 2 is a perspective view showing the evaporator of the firstembodiment.

FIG. 3 is a perspective exploded-view showing the upper portion of theevaporator of the first embodiment.

FIG. 4 is a perspective exploded view showing the lower portion of theevaporator of the first embodiment.

FIG. 5 is an enlarged side cross-sectional view showing the upper headermember of the evaporator of the first embodiment.

FIG. 6 is an enlarged side cross-sectional view showing the lower headermember of the evaporator of the first embodiment.

FIG. 7 is an enlarged cross-sectional view showing the heat exchangingtube applied to the evaporator of the first embodiment.

FIG. 8 is a perspective view showing the tube member applied to theevaporator of the first embodiment.

FIG. 9 is a perspective view showing the flow of the refrigerant in theevaporator of the first embodiment.

FIG. 10 is a graph showing the relation between a tube height and a heatexchange amount ratio in the evaporator of the first embodiment.

FIG. 11 is an exploded perspective view showing the upper portion of theevaporator which is a first modification of the present invention.

FIG. 12 is an enlarged side cross-sectional view showing the upperheader member of the evaporator of the first modification.

FIG. 13 is an exploded perspective view showing the upper portion of theevaporator which is a second modification of the present invention.

FIG. 14 is an enlarged cross-sectional view showing the upper headermember of the evaporator which is the second modification.

FIG. 15A is a front view showing the evaporator which is the thirdmodification.

FIG. 15B is a top view showing the evaporator which is the thirdmodification.

FIG. 16 is a plane view showing the uneven-distribution-flow preventingresistance plate of the evaporator which is a fourth modification.

FIG. 17 is a side cross-sectional view showing the outlet-side-tank ofthe upper header member in the evaporator of the first embodiment.

FIG. 18 is an enlarged side cross-sectional view showing the upperheader member of the evaporator which is the second embodiment of thepresent invention.

FIG. 19 is an enlarged side cross-sectional view showing the lowerheader portion member of the evaporator which is the second embodiment.

FIG. 20A is a side cross-sectional view showing a header plate in theupper header member of the second embodiment.

FIG. 20B is a plane view showing the header plate of the upper-headermember according to the second embodiment.

FIG. 21A is a side cross-sectional view showing the header cover of theupper header member of the second embodiment.

FIG. 21B is a front cross-sectional view showing the header cover of theupper header member of the second embodiment.

FIG. 22A is a side cross-sectional view showing the header plate of thelower header member of the second embodiment.

FIG. 22B is a plane view showing the header plate of the lower headermember of the second embodiment.

FIG. 23A is a side cross-sectional view showing the header cover of thelower header member of the second embodiment.

FIG. 23B is a plane view showing the header cover of the lower headermember of the second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

FIGS. 1 to 6 show an evaporator according to a first embodiment of thepresent invention. As shown in these figures, this evaporator is used asan evaporator for a refrigeration system for car air-conditioners. Asshown in these figures, the evaporator includes a core 1 constituting aheat exchanging portion, an upper header member 10 as aninlet-and-outlet-side header member disposed along the upper end of thecore 1 and a lower header member 50 as a refrigerant-turn-side headermember disposed along the lower end of the core 1 as a fundamentalstructure.

The core 1 is provided with a plurality of flat tubular elements 5 and aplurality of corrugated fins 2.

As shown in FIGS. 7 and 8, the tubular member 5 is constituted by anextruded molded article of aluminum or its alloy integrally providedwith a downstream-side flat heat exchanging tube 7 to be disposed at thefront row side of the core 1, an upstream-side flat heat exchanging tube6 arranged side-by-side with the downstream-side heat exchanging tube 7at the rear row side of the core 1 and a connecting piece 8 whichconnects these tubes 6 and 7.

Each heat exchanging-tube 6 and 7 is provided with a plurality of heatexchanging passages 6 a and 7 a arranged in parallel each other andextending along the longitudinal direction thereof (i.e., the directionof extrusion). On the inner peripheral surface of each heat exchangingpassage 6 a and 7 a, inwardly protruded inner fins 6 b or 7 b areintegrally formed.

The core 1 is formed by alternatively laminating the aforementionedtubular members 5 and corrugated fins 2 in the core width direction anddisposing a side plate 3 on the external side of the respectiveoutermost corrugated fin 2. Thus, each heat exchanging tube 6 located atthe upstream-side among the plurality of tubular members 5 form anupstream-side heat exchanging tube group as a first pass P1, while eachheat exchanging tube 7 located at the downstream-side form adownstream-side heat exchanging tube group as a second pass P2.

In this embodiment, it is preferable that the tube height H is set to0.75 to 1.5 mm. The lower limit of the tube height H is preferably setto 1.0 mm or more.

Furthermore, it is preferable that each width of the heat exchangingtube 6 and 7 is set to 12 to 18 mm. As for the tubular member 5integrally provided with the tubes 6 and 7, the width is preferably setto 32 to 38 mm. Furthermore, as for the wall thickness of the peripheralwall of the tube 6 and 7, it is preferable that the wall thickness isset to 0.175 to 0.275 mm. Furthermore, as for the wall thickness of thepartitioning wall for dividing the heat exchanging passage 6 a and 7 ain the tube 6 and 7, it is preferable that the wall thickness is set to0.175 to 0.275 mm, while the pitch of the partitioning wall ispreferably set to 0.5 to 3.0 mm. Furthermore, as for the radius ofcurvature R of the external side surface of the side portion of the heatexchanging tube 6 and 7, it is preferable to set to 0.35 to 0.75 mm.

Furthermore, the height (fin height) of the corrugated fin 2 ispreferably set to 7.0 to 10 mm, and the pitch (fin pitch) of the fin 2is preferably set to 1.3 to 1.8 mm.

That is, in cases where the structure falling within the numerical scopeis employed, good heat exchange performance can be obtained.

In this embodiment, although heat exchanging tubes 6 and 7 areintegrally formed, the present invention is not limited to it. Thepresent invention allows forming both the tubes 6 and 7 separately.Furthermore, the heat exchanging tube 6 and 7 is not limited to anextruded molded article. For example, the heat exchanging tube 6 and 7may be a bend-formed article having inner fins obtained by bending aplate member or a roll-formed article having a heat exchanging passageobtained by rolling a plate member.

Furthermore, in this invention, a plate fin may be used in place of thecorrugated fin 2.

As shown in FIGS. 1 to 6, the upper header member 10 is disposed alongthe upper end portion of the core 1 along the core width direction, andincludes a header plate 20, a header cover 30, a refrigerantdistributing resistance plate 41 and an uneven-distribution-flowpreventing resistance plate 42.

At the front-half region and the rear-half region of the header plate20, a plurality of tube mounting apertures 21 are formed at certainintervals along the longitudinal direction, respectively.

The header cover 30 is disposed so as to cover the upper surface side ofthe header plate 20 from the above. At the middle position of the lowersurface in the fore-and-aft direction, a partitioning wall 31 isintegrally formed so as to extend along the longitudinal direction (thecore width direction).

By the space surrounded by the header plate 20 and the header cover 30and positioned in front of the partitioning wall 31, an outlet-side tank12 having a tube shape and extending in the core width direction isformed. On the other hand, by the space surrounded by the header plate20 and the header cover 30 and positioned behind the partitioning wall31, an inlet-side tank 11 having a tube shape and extending in the corewidth direction is formed.

Furthermore, a refrigerant inlet 11 a is formed at the longitudinalmiddle portion of the header cover 30 of the inlet-side tank 11, while arefrigerant outlet 12 a is formed at the portion of the header cover 30of the outlet-side tank 12.

Furthermore, in the inlet-side tank 11, a refrigerant distributingresistance plate 41 is provided so as to divide the inner space into anupper space and a lower space. This refrigerant distributing resistanceplate 41 is equipped with a plurality of refrigerant passage apertures41 a formed at certain intervals in the longitudinal direction. In therefrigerant passage apertures 41 a, the diameter of the aperture 41 anear the refrigerant inlet 11 a, or the diameter of the aperture 41 alocated at the longitudinal central portion, is formed to be thesmallest, while the diameters of the other apertures 41 a are formed tobecome gradually larger as it goes toward the longitudinal end portionfrom the longitudinal central portion.

In the outlet-side tank 12, an uneven-distribution-flow preventingresistance plate 42 is provided so as to divide the inside space into anupper space and a lower space. This uneven-distribution-flow preventingresistance plate 42 is provided with a plurality of refrigerant passageapertures 42 a, which are the same in diameter, at certain intervalsalong the longitudinal direction.

Furthermore, as shown in FIG. 1, a header cap 15 is attached to each ofboth end openings of the upper header member 10 so as to air-tightlyseal each end opening.

Furthermore, to the refrigerant inlet 11 a and the refrigerant outlet 12a of the upper header member 10, joint tubes 11 b and 12 b are fixed soas to communicate with the inlet 11 a and outlet 12 a.

In this embodiment, the refrigerant distributing resistance plate 41 andthe uneven-distribution-flow preventing resistance plate 42 are formedseparately to the header plate 20 and the header cover 30. In thepresent invention, however, these resistance plates 41 and 42 may beintegrally formed with the header plate 20 and/or the header cover 30.Furthermore, the partitioning wall 31 may be integrally formed with theheader plate 20. Alternatively, the partitioning wall 31 may be formedas a separate member.

To each of the tube mounting apertures 21 of the header plate 20constituting the aforementioned upper header member 10, the upper end ofeach of the heat exchanging tubes 6 and 7 constituting theaforementioned core 1 is fixed in an inserted state. In this state, theupstream-side heat exchanging tubes 6 are communicated with theinlet-side tank 11, while the downstream-side heat exchanging tubes 7are communicated with the outlet-side tank 12.

On the other hand, as shown in FIGS. 4 and 6, the lower side headermember 50 is disposed at the lower end portion of the core 1 along thecore width direction, and has a header plate 60 and a header cover 70.

The header plate 60 is provided with a plurality of tube mountingapertures 61 arranged at certain intervals in the longitudinal directionthereof at the front half region and the rear half region thereofrespectively.

The header cover 70 is attached to the header plate 60 so as to coverthe lower surface of the header plate, and has, at the widthwise middleposition on the upper surface thereof, a partitioning wall 71continuously extending in the longitudinal direction of the header cover(the core width direction). This partitioning wall 71 is provided with aplurality of cut-out communication apertures 71 a at certain intervalsin the longitudinal direction.

By the space surrounded by the header plate 60 and the header cover 70and positioned behind the partitioning wall 71, an inflow-side tank 51having a tube shape and extending in the core width direction is formed.On the other hand, by the space surrounded by the header plate 60 andthe header cover 70 and positioned in front of the partitioning wall 71,an outflow-side tank 52 having a tube shape and extending in the corewidth direction is formed. In this case, the inflow-side tank 51 and theoutflow-side tank 52 are communicated by the cut-out communicationapertures 71 a formed in the partitioning wall 71.

Furthermore, as shown in FIG. 1, a header cap 55 is attached to each ofthe end openings of the lower header member 50 in an air-tightly sealedmanner. In the present invention, the partitioning wall 71 of the lowerheader member 50 may be integrally formed with the header plate 60 ormay be formed as a separate member.

To each of the tube mounting apertures 51 of the header plate 60 of theaforementioned lower header member 50, the lower end of each heatexchanging tube 6 and 7 is fixed in an inserted manner. In this state,the upstream-side heat exchanging tube 6 is communicated with theinflow-side tank 51 of the lower header member 50, while thedownstream-side heat exchanging tube 7 is communicated with theoutflow-side tank 52.

In the evaporator of the first embodiment constituted as mentionedabove, each component is made of aluminum or its alloy, or an aluminumbrazing sheet in which a brazing layer is laminated on at least onesurface of the brazing sheet. These components are provisionallyassembled together with brazing materials if necessary into apredetermined evaporator configuration. Then, this provisionallyassembled product is collectively brazed in a furnace to integrallyconnect the components.

In this invention, however, the method of connecting the components isnot specifically limited and may be performed by any known procedure.

The aforementioned evaporator is mounted as an automobile refrigerationcycle together with a compressor, a condenser and decompressing meanssuch that the front-face side (the downstream-side heat exchanging tubegroup side P2) and the rear-face side (the upstream-side heat exchangingtube side P1) constitute an air taking-in side and an air taking-outside, respectively.

Then, the mist-like two phase refrigerant including a liquid phase and avapor phase passed the compressor, the condenser and the decompressingmeans is introduced into the inlet-side tank 11 of the upper headermember 10 via the refrigerant inlet 11 a of the aforementionedevaporator.

The refrigerant introduced into the inlet-side tank 11 is distributed bythe refrigerant distributing resistance plate 41 in the longitudinaldirection of the tank 11 and passes through each refrigerant passageaperture 41 a of the resistance plate 41. At this time, the refrigeranttends to pass through the refrigerant passage apertures 41 a near therefrigerant inlet 11 a, i.e., the refrigerant passage apertures 41 alocated at the longitudinal middle portion, at a large rate because ofthe inertia. However, in this embodiment, since the flow velocity of therefrigerant decreases by the resistance plate 41, the refrigerantdistributes smoothly in the longitudinal direction and passes througheach refrigerant passage aperture 41 a. Furthermore, in this embodiment,the refrigerant passage aperture 41 a of the resistance plate 41 isformed to be small in diameter at the longitudinal middle portion, whilethe refrigerant passage aperture 41 a is formed to be larger as it goestoward the end portion of the resistance plate 41. Therefore, the volumeof refrigerant passing through each refrigerant passage aperture 41 a isrestricted moderately, and therefore the refrigerant equally passesthrough each refrigerant passage aperture 41 a. This also enables toeffectively distribute the refrigerant in the longitudinal direction ofthe inlet-side tank 10.

The refrigerant equally distributed by the resistance plate 41 isequally introduced into each tube 6 of the upstream-side heat exchangingtube group P1.

The refrigerant introduced into the upstream-side heat exchanging tubegroup P1 is introduced into the inflow-side tank 51 of the lower headermember 50 through each tube 6, and then introduced into the outflow-sidetank 52 through the cut-out communication apertures 71 a of thepartitioning wall 71.

Since the refrigerant passing through the upstream-side heat exchangingtube group P1 is equally distributed into each heat exchanging tube 6,the refrigerant is equally distributed and introduced into each tube 7of the downstream-side heat exchanging tube group P2 by passing throughthe inflow-side tank 51 and the outflow-side tank 52 s of the lowerheader member 50 while keeping the equally distribution state.

The refrigerant passed through each downstream-side heat exchanging tube7 is introduced into the outlet-side tank 12 of the upper header member10. In the outlet-side tank 12, the refrigerant receives a moderate flowresistance by the uneven-distribution-flow preventing resistance plate42, resulting in an equally balanced pressure of refrigerant at theentire longitudinal direction of the outlet-side tank 12, whichassuredly prevents uneven-distribution-flow of the refrigerant. Thus,the refrigerant flows out of the refrigerant outlet 12 a via eachrefrigerant passage aperture 42 a of the resistance plate 42.

Since the uneven-distribution-flow preventing resistance plate 42prevents the refrigerant from being unevenly distributed in theoutlet-side tank 12, the refrigerant is effectively prevented from beingunevenly distributed in the downstream-side heat exchanging tube groupP2. Thus, the refrigerant can pass through each heat exchanging tube 7at the downstream-side in an evenly distributed manner.

The refrigerant flowed out of the refrigerant outlet 12 a of the upperheader member 10 is returned to the compressor in the aforementionedrefrigeration cycle.

The refrigerant passing through the upstream and downstream-side heatexchanging tube groups P1 and P2 absorbs heat from the air A taken fromthe front-side of the core 1 and evaporates by exchanging heat with theair. Furthermore, the air A cooled by the heat absorption flows out ofthe rear-side of the core 1, and is sent to the interior of a car.

As mentioned above, according to the evaporator of this embodiment, therefrigerant passes through each heat exchanging tube 6 and 7 of theupstream-side and downstream-side heat exchanging tube groups P1 and P2in an equally distributed manner. Therefore, the refrigerant canexchange heat at the entire region of the heat exchanging tube groups P1and P2, i.e., the entire region of the core 1, resulting in an improvedheat exchange performance.

Furthermore, in this embodiment, since the refrigerant passes throughtwo tube groups P1 and P2 forming a simple U-shaped refrigerant passage,the refrigerant flow resistance can be decreased. As a result, thepassage cross-sectional area of the refrigerant can be decreased, andtherefore the tube height of each heat exchanging tube 6 and 7 can bedecreased. Accordingly, the size, weight and thickness can be furtherdecreased. Furthermore, by decreasing the tube height, the installationnumber of heat exchanging tubes 6 and 7 can be increased withoutchanging the evaporator size, resulting in further enhancedrefrigeration dispersibility, which in turn can further improve the heatexchange performance.

Furthermore, in the present embodiment, the partitioning wall 31disposed between the upper wall and the bottom wall of the upper headermember 10 continuously extends within the upper header member 10 in thelongitudinal direction, and the partitioning wall 71 disposed betweenthe upper wall and the bottom wall of the lower header member 50continuously extends within the lower header member 50 in thelongitudinal direction. Accordingly, these partitioning walls 31 and 71reinforce each header member 10 and 50, and therefore both the headermembers 10 and 50 can be improved in pressure resistance.

Furthermore, in this embodiment, a tubular member 5 which is formed byintegrally connecting the corresponding heat exchanging tubes 6 and 7 ofthe upstream-side heat exchanging tube group P1 and the downstream-sideheat exchanging tube group P2 is employed. Therefore, the upstream-sideand downstream-side heat exchanging tubes 6 and 7 can be formed bysimply laminating the aforementioned tubular members 5. As a result, theevaporator can be fabricated easily. Furthermore, since the heatexchanging tubes 6 and 7 are connected between the heat exchanging tubegroups P1 and P2, the strength of the assembly is increased.

Now, in the evaporator according to this embodiment, the relation of thetube height H of the heat exchanging tube and the heat exchanging amountratio % is shown in FIG. 10. As apparent from this graph, according tothe evaporator of the present invention, the heat exchanging amountratio is high at the tube height H falling within the range of 0.75 to1.5 mm. Therefore, a heat exchanging tube of such a tube height issuitably employed.

By the way, in a conventional heat exchanging tube used for theso-called header type heat exchanger, it is considered that the tubeheight preferably falls within the range of about 1.5 to 3.0 mm which istwice the height of the tube height of the evaporator according to thisembodiment.

Furthermore, in the aforementioned embodiment, although the refrigerantdistributing resistance plate 41 and the uneven-distribution-flowpreventing resistance plate 42 are provided in the inlet-side tank 11and the outlet-side tank 12 of the upper header member 10, the presentinvention is not limited to it. For example, as shown in FIGS. 11 and12, the uneven-distribution-flow preventing resistance plate 42 may beomitted. Alternatively, as shown in FIGS. 13 and 14, the-refrigerantdistributing resistance plate 41 may be omitted, or both of therefrigerant distributing resistance plate 41 and theuneven-distribution-flow preventing resistance plate 42 may be omitted.

Furthermore, in the aforementioned embodiment, although the refrigerantinlet 11 a and outlet 12 a are formed in the longitudinal middle upperportion of the upper header member 10, the present invention is notlimited to it. For example, as shown in FIG. 15, refrigerant inlets 11 aand 12 a may be formed at one end portion of the header member 10 sothat the refrigerant can be flowed into and out of the evaporator fromthe header end portion.

Furthermore, in the aforementioned embodiment, as shown in FIG. 16, therefrigerant passage apertures 42 a of the uneven-distribution-flowpreventing resistance plate 42 may be formed at the windward side of thewidthwise middle portion of the tube relative to the air taking-indirection of the evaporator. Furthermore, the refrigerant passageaperture 42 a may be formed into a circular shape, or an ellipse shapeor a rectangle shape having a major axis along the widthwise directionof the heat exchanging tube.

Furthermore, in the aforementioned embodiment, as shown in FIG. 17, itis preferable that the cross-sectional area S of the gap (shown byhatching in FIG. 17) formed between the resistance plate 42 and the endportion of the heat exchanging tube 7 in the outflow-side tank 12 of theupper side header member 10 is 1 to 5 times of the passagecross-sectional area of the heat exchanging tube 7. In cases where thisstructure is adopted, it is possible to prevent an increase of the flowresistance between the uneven-distribution-flow preventing resistanceplate 42 and the tube end portion and secure an appropriate space in theheader member.

Furthermore, in the evaporator of the aforementioned embodiment,although an air A is introduced from the downstream-side heat exchangingtube group P2 as an evaporator front side, the present invention is notlimited to it. In the present invention, an air A may be introduced fromthe upstream-side heat exchanging tube group P1 as an evaporator frontside.

Furthermore, in this embodiment, the installation direction of theevaporator is not limited to a specific direction, and the evaporatormay be installed at any direction.

Second Embodiment

FIGS. 18 and 19 show an evaporator of a second embodiment of the presentinvention. As shown in these figures, in the evaporator of thisembodiment, the header plate 20 and 60 and the header cover 30 and 70constituting the inlet-and-outlet side (upper side) header member 10 andthe refrigerant-turn-side (lower side) header member 50 are formed by apress-formed aluminum (or its alloy) plate respectively.

That is, as shown in FIGS. 18 to 20, the header plate of the upper sideheader member 10 and 20 is formed by bending an aluminum plate to whichperforation press forming is performed. By this press forming, aplurality of tube mounting apertures 21 are formed in the header plate20 in two rows front and rear at certain intervals along thelongitudinal direction and a plurality of engaging apertures 22 areformed at certain intervals along the longitudinal direction between thefront and rear rows of the tube mounting apertures 21.

As shown in FIG. 21, the upper header cover 30 is made of an aluminumplate member which is thinner than a plate member constituting theaforementioned header plate 20, and is formed by subjecting the aluminumplate member to bending processing after the prescribed perforationprocessing. This press forming forms the header cover 30 such that adownwardly protruded partitioning wall 31 formed by folding thewidthwise middle portion is formed and downwardly protruded engagingprotrusions 32 corresponding to the aforementioned engaging apertures 22of the header plate 20 are formed at the tip of each partitioning wall31.

This header cover 30 is fixed to the header plate 20 in a state that theheader cover 30 covers the upper surface side of the header plate 20 andthe tip of the engaging protrusion 32 of the partitioning wall 31 isinserted in the engaging aperture 22 of the header plate 20 and caulked.

In this state, at the front-side space of the partitioning wall 31surrounded by the header plate 20 and the header cover 30, anoutlet-side tank 12 of a tube shape extending in the core widthdirection is formed, while at the rear-side space of the partitioningwall 31 an inlet-side tank 11 of a tube shape extending in the corewidth direction is formed.

As shown in FIG. 22, the lower side header plate 60 of the lower headermember 60 is formed by subjecting an aluminum plate to a perforationprocessing and bending processing in the same manner as in theaforementioned header plate 10. By this press forming, a plurality oftube mounting apertures 61 are formed in the header plate 60 in two rowsfront and rear at certain intervals along the longitudinal direction anda plurality of engaging apertures 62 are formed at certain intervalsalong the longitudinal direction between the front and rear rows of thetube mounting apertures 61.

As shown in FIG. 23, the lower header cover 70 is made of a thinaluminum plate member formed by subjecting the aluminum plate member toperforation processing and bending processing in the same manner as inthe header cover 30. This press forming forms the header cover 70 suchthat an upwardly protruded partitioning wall 71 formed by folding thewidthwise middle portion is formed and upwardly protruded engagingprotrusions 72 corresponding to the engaging apertures 62 of the headerplate 60 are formed at the tip of each partitioning wall 71.Furthermore, in the partitioning wall 71, cut-out communicationapertures 71 a are formed at certain intervals along the longitudinaldirection.

This header cover 70 is fixed to the header plate 60 in a state that theheader cover 70 covers the lower surface side of the header plate 60 andthe tip of the engaging protrusion 72 of the partitioning wall 71 isinserted in the engaging aperture 62 of the header plate 60 and caulked.In this state, at the rear-side space of the partitioning wall 71surrounded by the header plate 60 and the header cover 70, aninflow-side tank 51 of a tube shape extending in the core widthdirection is formed, while at the front-side space of the partitioningwall 71 an outflow-side tank 11 of a tube shape extending in the corewidth direction is formed. Furthermore, the inflow-side tank 51 and theoutflow-side tank 52 are communicated with each other via communicationapertures 71 a formed in the partition 71.

Then, as shown in FIGS. 18 and 19, the upper and of each heat exchangingtube 6 and 7 of the same core 1 as in the first embodiment is insertedinto each tube mounting aperture 21 of the header plate 20 of the upperheader member 10 and fixed thereto, while the lower end of the heatexchanging tube 6 and 7 is inserted into each tube mounting aperture 61of the header plate 60 of the lower header member 50 and fixed thereto.

Since the other structure is essentially the same as in the firstembodiment, the duplicate explanation will be omitted by allotting thesame reference numeral to the same or corresponding portion.

In this evaporator of the second embodiment, in the same manner as inthe first embodiment, the evaporator components are provisionallyassembled into a predetermined evaporator configuration, and theprovisionally assembled product is collectively brazed in a furnace tothereby integrally connect them.

According to the evaporator of this second embodiment, the same effectsas in the first embodiment can be obtained.

Moreover, since an aluminum press-formed plate member is used as thestructural member 20, 30, 60 and 70 of each header member 10 and 50, theheader structural member 20, 30, 60 and 70 can be continuouslymanufactured from a coiled aluminum member, resulting in an enhancedproductivity.

Furthermore, since the header structure member 20, 30, 60 and 70 is madeof a plate member, a brazing sheet having clad materials such as brazingmaterials or sacrifice materials laminated on at least one side surfacethereof can be used as the header structure member 20, 30, 60 and 70,resulting in an enhanced brazability. Especially, in cases wherecladding materials are laminated on the external surface side, thecorrosion protection nature can be improved by containing zinc (Zn) intothe cladding materials to thereby form a sacrifice material layer.

Furthermore, since the partitioning wall 31 and 71 of both the headermembers 10 and 50, sufficient strength can be secured while decreasingthe header height and the wall thickness, resulting in a reduced sizeand weight. Especially, since the partitioning wall 31 and 71 is formedby folding a plate member, sufficient strength can be secured even ifthe thickness is thin, which enables to further decrease the size andweight.

In the second embodiment, the refrigerant distributing resistance plate0.41 and the uneven-distribution-flow preventing resistance plate 42 maybe provided in the header member 10 and 50 in the same manner as in thefirst embodiment.

Furthermore, in this embodiment, although the header plate 20 and 60 andthe header cover 30 and 70 constituting the header member 10 and 50 areformed by an aluminum plate respectively, in the present invention, apart of these members may be made of an extruded molded article.

In cases where an extruded molded article is used as a part of headerstructure member, it is difficult to form a sacrifice layer by itself.Therefore, before subjecting it to collective brazing processing, a fluxcontaining zinc is applied to the extruded molded article. This enablesto form a zinc diffusion layer (sacrifice layer) on the externalsurface, resulting an improved corrosion resistance.

Furthermore, in the second embodiment too, in the same manner as in thefirst embodiment, the position of the refrigerant inlet and/or therefrigerant outlet, the air take-in direction and the installationdirection of the evaporator are not specifically limited.

As mentioned above, according to the first to fourth aspect of thepresent invention, since the refrigerant passage is formed into a simpleU-shape, the refrigerant flow resistance can be decreased. As a result,the refrigerant flow cross-sectional area can be decreased and the tubeheight of the heat exchanging tube can be decreased. Accordingly, thesize, weight and thickness of the evaporator can be reduced.Furthermore, in cases where the tube height is decreased, the number oftubes can be increased without increasing the core size. Therefore, therefrigerant dispersibility can be improved, resulting in improved heatexchanging performance. Especially, according to the evaporator of thethird and fourth aspect of the present invention, since the headermember is made of a metal press-formed plate, the productivity can beimproved and the brazability and corrosion resistance can also beimproved by using a brazing sheet.

The fifth to eighth aspect of the present invention specify amanufacturing process of the evaporator of the first to fourth aspect ofthe present invention. Therefore, the aforementioned evaporator can bemanufactured more assuredly.

Furthermore, the ninth and tenth aspects of the present inventionspecify a header member applicable to the evaporator of the third orfourth aspect of the present invention. Therefore, the aforementionedevaporator can be manufactured more assuredly.

The eleventh to fourteenth aspects of the present invention specify arefrigerant system using the evaporator of the first to fourth aspect ofthe present invention. Therefore, the aforementioned effects can beobtained more assuredly.

The terms and expressions which have been employed herein are used asterms of description and not of limitation, and there is no intent, inthe use of such terms and expressions, of excluding any of theequivalents of the features shown and described or portions thereof, butit is recognized that various modifications are possible within thescope of the invention claimed.

INDUSTRIAL APPLICABILITY

As mentioned above, the evaporator, the manufacturing method thereof,the header member for evaporators and a refrigeration system can improveheat exchanging performance while reducing the size and weight.Therefore, they can be preferably used for a refrigeration cycle for carair-conditioning system especially.

1. A refrigerant-turn-side header member for an evaporator with a coreincluding an upstream-side heat exchanging tube group and adownstream-side heat exchanging tube group disposed front and rear, eachof said heat exchanging tube groups including a plurality of heatexchanging tubes arranged in parallel with each other at certainintervals, said header member comprising: a header plate for fixing anend portion of each of said heat exchanging tubes in a penetratedmanner; a header cover attached to said header plate so as to cover onesurface side thereof; and a partition for forming an inflow-side tankand an outflow-side tank by dividing a hollow portion surrounded by saidheader plate and said header cover front and rear, said partition havingcommunication apertures for communicating with said tanks; wherein atleast one of said header plate and the said header cover is apress-formed metal plate, and wherein refrigerant passing through saidupstream-side heat exchanging tube group is introduced into saidinflow-side tank and then introduced into said outflow-side tank viasaid communication apertures, while said refrigerant in saidoutflow-side tank is introduced into said downstream-side heatexchanging tube group.
 2. The refrigerant-turn-side header member for anevaporator as recited in claim 1, wherein both of said header plate andsaid header cover are formed by a press-formed metal plate memberrespectively, and wherein said partition is integrally formed with saidheader cover by folding a widthwise middle portion of said metal plateconstituting said header cover along a longitudinal direction thereof.3. The refrigerant-turn-side header member for an evaporator as recitedin claim 1, wherein one of said header plate and said header cover is apress-formed metal plate, and the other thereof is an extruded moldedarticle.